Indeed, the buttons of the RadToolBar do not have client IDs. However, you can either assign such on the server or create the tooltip dynamically on the client. For such cases we have prepared the following demos which show both the appraches:
They are tooltipifying calendar and treeview but the core logic is absolutely the same in your case as well.
Please, examine the code and use it as a start point for your implementation.
On a side note, when you install RadControls, our online examples projects are automatically installed on your computer and you can not only examine their full source code, but also extend them further in order to meet your requirements.
You can open the demos from here:
Start\Programs\Telerik\RadControls for ASPNET AJAX\Open Sample WebSite In VisualStudio
The actual location on your hard disk is the following one:
C:\Program Files\Telerik\RadControls for ASPNET AJAX \Live Demos
I hope that this information is helpful, let me know if you have additional questions or you need further assistance.
All the best,
the Telerik team
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